1. Field of the Invention
The present invention relates to a communication antenna, an RFID tag that is communicated by the communication antenna, a non-contact communication device and a non-contact communication method.
2. Description of the Related Art
Various types of measures have been thought of for making a single RFID tag be the object of communication when plural RFID tags are formed in parallel in a transverse direction on an insulating substrate such as a film or the like and communication is carried out for inspection or the like while these plural RFID tags are conveyed in order (see, for example, Japanese National Publication No. 2008-519500, and Japanese Patent Applications Laid-Open (JP-A) Nos. 2005-284331, 2004-220141, and 2005-328259). The technique of Japanese National Publication No. 2008-519500 makes an antenna for carrying out communication with an RFID tag be a near field microstrip antenna. The technique disclosed in JP-A No. 2005-284331 varies the conveying path of a continuous sheet such that, among plural non-contact IC labels that are formed in the form of a continuous sheet, only the non-contact IC label that is the object of communication faces an antenna for communication. In the technique disclosed in JP-A No. 2004-220141, a radio wave absorbing plate having a slit is disposed between an antenna for communication and plural IC inlets that are formed on an insulating film, and the antenna for communication is made to communicate with only a specific IC inlet through the slit of the radio wave absorbing plate. In the technique disclosed in JP-A No. 2005-328259, due to the arrangement of a reflecting means, that reflects radio waves radiated from an antenna, and a conveying path of RF tags with respect to the antenna, radio waves having high electric field intensity are provided to a specific RF tag from the reflecting means.
However, there is room for further improvement in carrying out communication individually with respect to plural RFID tags.